diff options
Diffstat (limited to 'drivers/usb')
| -rw-r--r-- | drivers/usb/host/xhci-ring.c | 25 |
1 files changed, 13 insertions, 12 deletions
diff --git a/drivers/usb/host/xhci-ring.c b/drivers/usb/host/xhci-ring.c index 4194f348e3a7..6bd9d53062eb 100644 --- a/drivers/usb/host/xhci-ring.c +++ b/drivers/usb/host/xhci-ring.c @@ -249,16 +249,24 @@ static void inc_enq(struct xhci_hcd *xhci, struct xhci_ring *ring, } /* - * Check to see if there's room to enqueue num_trbs on the ring. See rules - * above. + * Check to see if there's room to enqueue num_trbs on the ring and make sure + * enqueue pointer will not advance into dequeue segment. See rules above. */ static inline int room_on_ring(struct xhci_hcd *xhci, struct xhci_ring *ring, unsigned int num_trbs) { - if (ring->num_trbs_free >= num_trbs) - return 1; + int num_trbs_in_deq_seg; - return 0; + if (ring->num_trbs_free < num_trbs) + return 0; + + if (ring->type != TYPE_COMMAND && ring->type != TYPE_EVENT) { + num_trbs_in_deq_seg = ring->dequeue - ring->deq_seg->trbs; + if (ring->num_trbs_free < num_trbs + num_trbs_in_deq_seg) + return 0; + } + + return 1; } /* Ring the host controller doorbell after placing a command on the ring */ @@ -2529,13 +2537,6 @@ static int prepare_ring(struct xhci_hcd *xhci, struct xhci_ring *ep_ring, return -ENOMEM; } - if (ep_ring->enq_seg == ep_ring->deq_seg && - ep_ring->dequeue > ep_ring->enqueue) { - xhci_err(xhci, "Can not expand the ring while dequeue " - "pointer has not passed the link TRB\n"); - return -ENOMEM; - } - xhci_dbg(xhci, "ERROR no room on ep ring, " "try ring expansion\n"); num_trbs_needed = num_trbs - ep_ring->num_trbs_free; |